The US / Canadian markets in this context is somewhat obscure to me, as a european, where most machinery is either 230V or 400V for heavier stuff. I also notice they are used more and more as 3 phase converters, where 3-phase is not available. In theory, they should give full torque at any speed, but guess that is a truth with some mod's to it, even if this is where they really excel. I do have some experience with VFDs, as I have used them for test rigs where we needed vairable speed.
